The work has been pushing me down and down.

I got a job more than a year ago, I thought it was really good one. But I am wrong. I made mistakes when I work but all the time, especially when some of them are not from me.
I was told to criticize myself and look deep inside me. What I found? I felt myself miserable, I lost my confidence. And why I should do that? They are not my fault when project goes wrong!
Almost everything wrong was because of me, they blame me. I think I am a softy, I shouldn't have allowed them to do this to me!

Being blame for mistake you didn't do is very annoying and hurting. I'm facing a same kind and even worst situation at work (1 of my discussion).If you were told to critize yourself and look deep inside you, I think that is just rubbish. Who the hell is he/her to ask you anyway...I always believe nobody has a right to judge you more than they judge themselves. Everyone makes mistake, no matter what we are doing for life..I hope thing will gets better for you, and that you will know what exactly to do soon :)

The supervisor who blame me for everything knows nothing about database, he gives me "instructions" which are even make sense. He asked me to modify the source code in a few hours, however it should take a week to have it done. I didn't have my lunch for several days and once I worked till 9 o'clock and arrived home at 11 at night.
I agree with you, they said we cared about you. They all said you had changed, and become irresponsible.
But I realized who the hell gave them the right to ask me to criticize myself??? They said "care about me". That's rubbish, you are quite right mate!
After several times that I blamed myself, and misjudge myself, they did even worse to me.

If this was done to myself, and if they said they cared about me but I had changed and became irresponsible..I don't think I can find any other way of how to smile at them again. Honestly, it's not because it's hurting my pride, not at all..I'm sure not to you as well. But not having lunch for several days and getting back home at 11 at night ( are you working 9-5 ), OK I probably can squeeze my heart and try to take it, but getting blamed that way and misjudging you everyday, this is no way near to helping your staff to be more professional emotionally and physically. There must be something that they feel really insecure about at work and end up by relying on you which they found you as easily to be blamed as well - maybe (Try to search this one, as this is very important if you wanna stay with them). If I was right (hopefully), and if you can dig the answer, then that means you got your key....and the supervisor lost his master key :)

If you cannot stand up to them then I would try to find new work. I know about being blamed for something someone else did even if something easily fixed & the person said "Hey it was me that messed that up" you are still to blame then it's time to move on. Find a new employer if you can and stop working somewhere that plays the blame game & makes you feel bad about yourself.

I realized that after several times, and when I started to know how the person really is. But he actually threatened me.
One day he told me you can choose to leave, and you know I can always find another one to replace your position. But later he said: but if you leave and when ACS(Australian Computer Society) call me, I will say this man is not in our company and he is not capable of working for us. He would be scared if I leave, because half of the work is done by me, but I got, I guess one forth of salary he got.
Now I am fired, but I think that's the boss who made the decision, because there would be 2 weeks notice and that's the time for me to hand over my work. That's ridiculous for such a massive and detailed work. My supervisor knows nothing about the techniques I am using for the project.
I really expect to know what would happen after 2 weeks.

You either need to start looking for another workplace or put your union to work! Your union will deal with the people giving you a hard time and other employees seem to be really intimidated by this. Go to your union rep and file a couple of complaints.
Hold your head up high! Don't be pushed around work or no work. You're only trying your best and you're only human
Take care